Is Caffeine Effective In Reducing Pain Perception During Exercise Performance In Healthy Adults?

OBJECTIVE: The objective of this selective EBM review is to determine whether or not caffeine products are effective in reducing pain perception during exercise performance in healthy adults. STUDY DESIGN: Systematic review of three English language, randomized controlled trials published in 2012 and 2013. DATA SOURCES: Three randomized control trials (two double-blind and one single-blind) which compare caffeine administration to placebo for reduction in pain perception during exercise performance in health adults were obtained using PubMed. OUTCOMES MEASURED: Clinical outcomes of leg pain perception experienced during exercise were measured according to a Pain Intensity Scale, ranged 0-10, developed by Cook et al. (1998). RESULTS: Duncan & Hankey (2013) showed that caffeine ingestion prior to exercise reduced leg muscle pain perception in regularly active adults (p= \u3c0.01) compared to placebo group. Two studies by Astorino et al (2012) showed no significant reduction in leg pain perception during exercise that followed caffeine ingestion (F5,75 = 2.04, p = 0.16, ƞ2 = 0.12; F1,9= 0.96, P = 0.35, ƞ2= 0.10). CONCLUSIONS: The results of the RCTs show that the efficacy of caffeine ingestion prior to exercise performance in reducing leg pain perception is debatable based on opposing results from recent research on this matter. A common limitation to these studies is the small sample size – future studies are needed to incorporate greater sample sizes and incorporation of subjects of different fitness levels to improve generalizeability of results to the general population